[FEATURE]: Complete Desktop workflow for Anthropic-compatible custom providers #34004

Description

• I have searched the existing issues and found similar feature requests, but this appears to describe a different problem.

Summary

Issue #11692 ("Add Provider Type in custom provider") appears to have introduced backend support for Anthropic-compatible providers. However, the Desktop UI and current documentation do not provide a complete workflow for configuring them.

As a result, Anthropic-compatible providers are supported by the runtime but are extremely difficult to discover and configure.

Environment

• OpenCode Desktop: v1.17.11
• Operating System: Debian GNU/Linux 13 (trixie) x86_64

Problem

While integrating OpenModel's Anthropic-compatible API, I initially concluded that Anthropic-compatible custom providers were unsupported.

After extensive debugging, I discovered they actually work correctly.

The working configuration required manually editing:

• ~/.config/opencode/opencode.jsonc
• ~/.local/share/opencode/auth.json

Specifically, I had to:

• configure the provider using npm: "@ai-sdk/anthropic"
• set the base URL to https://api.openmodel.ai/v1
• manually create the provider credential inside auth.json

Without manually editing these internal files, I was unable to configure the provider through the Desktop UI.

Additionally, following the current documentation led me to try using:

"options": {
  "apiKey": "{env:ANTHROPIC_API_KEY}"
}

However, on OpenCode Desktop v1.17.11 this property is rejected by the Desktop configuration validator, making the documented approach unusable.

Expected Behavior

The Desktop application should provide a complete workflow for Anthropic-compatible custom providers similar to the existing OpenAI-compatible workflow.

For example:

• Add Anthropic-compatible provider
• Enter Provider ID
• Enter Display Name
• Enter Base URL
• Enter API Key
• Save credentials
• Provider automatically appears in /models

No manual editing of internal configuration files should be required.

Actual Behavior

The runtime already supports Anthropic-compatible providers, but the Desktop configuration workflow is incomplete.

Users must manually discover and edit internal configuration files before the provider becomes usable.

This makes the feature appear unsupported even though it already works.

Why this matters

This is primarily a discoverability and UX issue rather than a backend feature request.

The runtime already supports Anthropic-compatible providers, but the Desktop experience strongly suggests they are unsupported.

I spent a significant amount of time debugging this before discovering that the functionality already exists.

Improving the Desktop UI and documentation would make this existing capability much easier for users to access and would reduce confusion for anyone integrating Anthropic-compatible providers such as OpenModel.

Plugins

None

OpenCode version

v1.17.11

Steps to reproduce

1. Install OpenCode Desktop v1.17.11.

2. Attempt to configure an Anthropic-compatible provider (for example, OpenModel).

3. Follow the current documentation.

4. Observe that there is no complete Desktop workflow for configuring the provider.

5. Manually configure:

   • ~/.config/opencode/opencode.jsonc
   • ~/.local/share/opencode/auth.json

6. Restart OpenCode.

7. Observe that the provider now works successfully.

Screenshot and/or share link

No response

Operating System

Debian GNU/Linux 13 (trixie) x86_64

Terminal

Konsole